The invention concerns piston/cylinder assemblies.
As a rule, a piston/cylinder assembly consists of a cylinder and a piston that is received for sliding movement along the cylinder and is affixed to a piston rod that extends out of the cylinder. Connecting members on the cylinder and on the outer end of the piston rod serve to connect the piston/cylinder to elements that are axially movable relative to one another.
A vibration damper for a motor vehicle chassis is an example of a piston/cylinder assembly. A fundamental problem with vibration dampers is the production of a large damping force with small cylinder diameters. One possibility is to use relatively thick piston rods whose displacing volume figures significantly in the calculation of damping forces. However, doing so is associated with a requirement for considerable radial installation space since the piston rod also requires a piston rod guide and piston rod seal. Moreover, an equalization chamber must also be present for the displacing volume, which further increases the space requirement.
A similar problem exists for gas springs. The principal structure is comparable to a vibration damper. Rather than a damping force, a compression or tension force is intended to be available for use, which is calculated from the area of the piston rod cross section exposed to pressure multiplied by the operating pressure in the cylinder. In this application, too, a large piston rod diameter is desirable on the one hand, but is limited by the installation space generally available.